1. Field of the Invention
This invention relates to transmission line fault location systems and, in particular, to a method and an apparatus for determining on which side of the apparatus the fault is located.
2. Description of the Prior Art
The present invention can best be understood by reference to its application in a particular industry. In telephone subscriber loops, many subscribers provide their own terminal equipment and install their own wiring inside of their premises. A problem then arises of being able to isolate faults occurring in the telephone subscriber loop as being located within the subscriber's premises, in the inside wiring or the terminal equipment, or being located in that section of the subscriber loop outside the subscriber's premises which is owned by the telephone company. Furthermore, accurate fault location is also useful to a telephone company for dispatching the appropriate repairperson to correct the fault. Accordingly, it is necessary to provide an apparatus at the interface between the loop sections. Similar problems arise in other transmission systems where it is desirable to locate a fault in one or the other section of the transmission line, e.g., aerial or underground sections, within or outside of buildings, diversely owned sections, and so forth.